Nafion-assisted synthesis of palladium nanonetworks as efficient electrocatalysts for hydrogen evolution reaction

In this work, we synthesized a Pd nanonetwork (PdNN) catalyst by employing Nafion as structure-directing agent. The nanonetwork-like structure is interconnected by Pd particles. Moreover, the morphologies and the sizes of PdNN samples can be tunable by adjusting concentrations of Pd precursor. The as-prepared PdNN catalysts have superior hydrogen evolution reaction (HER) performance to that of commercial Pd/C. Among them, PdNN-4.5 catalysts exhibit the most excellent hydrogen evolution performance, which contains an overpotential of 59 mV at 10 mA cm^-2 and a Tafel slope of only 54 mV dec^-1. Besides, a super stability is also displayed for PdNN-4.5 catalysts. The significant improvement in the HER performance of the PdNN-4.5 catalyst may be attributed to the nanonetwork-like structure, the sizes, and the interaction between the Pd catalysts and Nafion. Thus, this work can provide a simple method for synthesizing the highly efficient Pd-based catalyst for HER.